The task of storing oil in tanks is important and relevant to many of industries including oil production, energy, mechanical engineering, and the like. Often, oil and oil products are stored in metal tanks for relatively long periods of time. Thus, the task of oil storage in tanks includes many subtasks that are based on properties of oil. One such subtask is heat insulation of tanks. Because oil may freeze at temperatures between −60 degrees Celsius (−60° C.) and 30° C., and because it may begin to boil at temperatures as low as 28° C., depending on its contents, requirements for controlling the temperature inside the tank are relatively strict. Moreover, the task of heat insulation is significantly complicated in oil producing sites with harsh and often extreme natural conditions.
To resolve the task of tank heat insulation, the range of materials and structures varies significantly depending on natural conditions and other factors. Traditionally, polyurethane, mineral wool plates, cellular glass, and the like are used as heat-insulating materials. Cellular glass is the most suitable material in extreme weather conditions. This is because heat-insulating and mechanical characteristics of cellular glass do not change over a relatively large range of temperatures and humidity. Another important factor is that cellular glass is a noncombustible material. The high risk of fire associated with oil and oil product tanks is taken into account during selection of materials and heat-insulating methods.
Various solutions are known in the art for insulation of such tanks.
U.S. Pat. No. 4,073,976 (published on 14 Feb. 1978, IPC F17C13/00) discloses a tank (for storage of the liquefied gas) where foam glass blocks are used as a load-bearing insulation at a bottom of the tank. The blocks are covered by a layer of vermiculite particles that provide for higher resistance to a pressure load.
U.S. Pat. No. 4,062,468 (published on 13 Dec. 1977, IPC B65D90/06) discloses an insulation system for big tanks that store fuel. The aim of the disclosure is to increase the cost effectiveness of insulation and its resistance to natural effects. The insulation includes panels of foam glass insulating material fixed on the tank wall and supported by metal rails. A layer of resinous material reinforced by fiber cloth is positioned on an exterior of the insulation.
U.S. Pat. Pub. No. 2012/0325821 (published on 27 Dec. 2012, IPC F17013/00) discloses a cryogenic tank that includes a welded internal tank and an outer shell that surrounds the welded internal tank. The tank also includes concrete foundation that includes a raised part. The tank also includes multiple cellular glass blocks installed on the raised part of the concrete foundation and a leveling concrete layer that coats the top layer of the foam glass blocks. The tank also includes a fastening device fixed in the concrete foundation. The welded internal tank is installed on the leveling concrete layer and an external shell is fixed on the fastening device along the perimeter of the external shell. The annular space between the internal tank and the external shell is filled with perlite.
R.F. patent No. 117467 (published on 27 Jun. 2012, IPC E04B1/76) discloses a heat-insulated coating that includes \foam glass blocks made in shape of a compressed prism. Liquid ceramic heat insulation is used to fasten foam glass blocks to the foundation of the protected structure and to each other.
U.S. Pat. No. 8,381,939 (published on 26 Feb. 2013, IPC E03B11/00) discloses an insulated storage facility that includes modular panels and structures that are stiff enough to store hot and cold liquids. The insulated storage facility is includes multiple insulating panels installed on an insulated supporter to form a cylindrical wall. Insulating panels have a relatively hard structure and support an internal pad. The cylindrical wall of insulating panels is supported by a thin external case. This insulated storage facility also includes a lid supported by insulating panels and that covers the contents of the storage facility.
However, known technical solutions do not provide structural elements that compensate for deformations of the wall of the protected structure during its operation. If deformations of the tank wall appear, the risk of destruction of the heat-insulated layer is high. Moreover, solutions do not provide the quick access to the surface of the tank for its technical maintenance and repair.
U.S. Pat. No. 8,615,946 (published on 31 Dec. 2013, IPC E04B7/00) discloses an insulated wall system that may be used as heat insulation of industrial structures. Heat insulation includes heat-insulating blocks made of any insulating material known in this field, including but not limited by polystyrene, polyurethane, polyisocyanurate, their mixtures, or the like. The insulated wall system includes many metal gratings installed parallel to and separated from each other. The system also includes multiple external panels, each of which is attached to metal gratings formed on the external coating. The system also includes multiple heat-insulating blocks each of which is installed between the metal grating and the external panel. The system also includes a plank between the heat-insulating blocks and the external panel, the plank having a step that fixes the heat-insulating block and decreases mutual side movements of the heat-insulating block and the plank. The system also includes a fastener that fastens the external panel, the plank and the heat-insulating block together with the metal grating. An adhesive layer may be used between the block and the metal grating to make the assembly of the insulated wall simpler. The adhesive material may include, for example, contact adhesives, reactive adhesives (for instance, epoxy resin, acrylate etc.), pressure sensitive adhesives, hot-melt adhesives, or the like.
The drawback of this technical solution is that the structure is extra hard, which may lead to destruction of the hard heat-insulating material where the tank wall has been deformed during operation.
The technical solution that is the closest to the present solution is a heat-insulated tank known disclosed by RF patent No. 2079620 (published on 20 May 2007, IPC E04H7/04). The tank includes elements tightly fixed on the tank body as horizontal bandages with a coat, and heat-insulating panels installed on them. The bandages are made as angles, fixed on the tank body using preassembled supports. The bandages are along a height of the body at distances between 2 meters (m) and 4 m above each other. The heat-insulating panels are formed as semi-hard mineral or slaggy blocks.
However, this technical solution does not provide adequate strength and safety of the tank heat insulation under loads caused by filling or discharge of the raw material or by environmental factors.